Fuse device



' Dec. 12, 1944.- w o SCHULTZ 2,365,113

FUSE DEVICE Filed Oct. 10; 1941 4 Shets-Sheet 1 IN VEN TOR.

WILL/HM 0. JCWHLTZ BY fx'rromv Dec. 12, 1944.

w. p. SCHULTZ 2,365,113

FUSE DEVICE Filed Oct. -1o, .1941 4 Sheets-Sheet 3 IN V EN TOR. Y W/Z 1/14/11 0 867/002 ATTOR EY.

occurs on large overloads. I load occurs, the expulsion action of the fuse tion of drope'out fuse devices. to thereof, and to accomplish both ofthese objects ,iriabove enumerated.

( operative position.

. ma ed Dee. 12, 1944 UNITED STATES PATEN T OFFICE 7 j 2,365,113 1 v l p FUSE nnvros William 0. Schultz. South Milwaukee. Wis.. as-

signorto Line Material Company, South Milwaukee. Wis., a corporation of Delaware 7 Application October 10, 1941, Serial No. 414,444

. 2?. Claims. (chase-114) This; invention relates to fuse devices. "Objects of this invention are to increase the rupturing capacity of fuse devices, to lessen the v internal pressure generated by the violent-explosionson large overloads,-and to thereby increase the safety against bursting of the fuse tube, and to provide for a. quicker and more positive interruption of the circuit within the fuse tube on either small or large overloads.

' A further ob ect is to provide for the positive detaching of a drop-out fuse tube from one of the stationary terminals to thereby insure the positive removal of the fuse tube-from its operatlve'iposition between the terminals upon the occurrence of an overload after first having interrupted the circuit within the fuse tube in a positive and. quick manner; Further objects are to provide fuse link extracting means for expulsion fuse devices which are so constructed that they insure a quick interruption of the circuit within-the fuse tube upon overload and a positive withdrawal of a pflrtion'at least of the fuse link within .the' fuse tube, such fuse link extracting means upon light overloads having a positive spring action to withdraw the fuse'link and, upon heavy overloads having this action augmented by the gas pres nsure acting upon the fuse link extracting means.

In drop-out fuse devices of the expulsion type in which the fuse tube ismo'unted on a pivot or hinge, damage to parts of the. device sometimes When a violentovertube is. great'and' there is a violent upward recoil followed bya violent downward rebound Figure 3 is a sectional view on the line 3-4 of Figure 1'.

- Figure4 is a view of the upper end of the fuse I tube after it has been refusedand while-it is Figure 5 shows the construction of Figure'l tion.

Figure 6 is a view of the-lower end of the device shown' in Figure 1 after the fuse tube .has rocked to its lowest positionwith a part of the lower stationary terminal in section.

Figure! is a view of a further form of the invention, with parts broken away and in section.

I which frequently-results in to theftennig nals 'and'especially to the lower hinge which supports these drop-out fuse tubes.

Further objects of this invention are to pro vide a novel. construction of drop-out fuse device of the expulsion't in which the fuse tube is allowed to-discharge from both ends'to thereby more or less. equalize themechanical thrust exerted on the fuse tube-to thereby lessen both" the upward recoil and. the downward rebound Figure 8 shows a. further formof the invention, with parts broken away and in section.

Figure 9 shows a further form of the invention in which the upper end of the fusetube is closed and is provided with a rigid contact. Figure 10 is a front view shown in: Figure 9. I

Referring to the drawings, particularly Figures 1 to 6, inclusive, where one form of the invention is shown, it will be seen that the drop-out fuse of the structure comprises a fuse tube I formed of insulating -material which is provided with upper and lower terminal contact assemblies indicated generally at 2 and 3 which engage upper and lower stationary terminals 4 and -5. The stationary terminals are carried from any suitable insulating support such as the elongated insulator B which may in tum-be supported by a bracket 1 clamped to the' insulator intermediate its ends.

V view being taken along the line 2-2 01? Figure 5.

..removed from the stationary supporting meanfl The upper stationary terminal. 4 may 'be a hood likestruc e as shown in Figures- 1, 3 and 5. or it may e an open structure as shown in Figure 7 hereinafter described.

This hood. like member is provided with a.

transversely extending cam like latching lip 8 which projects downwardly interiorly thereof und is provided with a slantingouter face and with consequent increase in safety of the parts the. entire apparatus.

of the-device and lessening of strainiinposed on Furtherjobjects are to--simpl y-' the1consti'uclessen the best while securing the advantageous features here- Embodiments of theinventi'on are shown in;

"the accompanylngdr'awings, in which:

Figure 2 is a viewof $116 "per lever at theupperleud of thefuse tube, such a, somewhat rounded inner face. I The lower, stationary terminal 5 consists of a pair of hook like portions as indicated which are adapted to re ceive 'trunnions 9 carried by the lower terminal assembly 3 of the "drop-out fuse tube. This lower terminal assembly is provided with r 5 w th the fuse tube has been rocked" down- 'wardly to approximat'elythe positionas'shown underside of the uped to receive the end of the switch stick s'othat in Figured-at, which time it may be unhooked from" the lower pair of hook members constitutthe fuse tube may be from rounded portion In which prevents'reinoval' of the fuse tube from the lower stationary-terminal Q Wer v Q nal member for refusing and may be replaced by means of-the switch. stick afterit has been refused. The lower terminal 3 of the fuse tube is provided with a thumb nut l2 threaded on a. projecting stem rigid with the lower terminal assembly 3 of the fuse tube so that the flexible leader l3 of the fuse link may be clamped in place.

The upper terminal assembly of'the fuse tube is provided with a sleeve or cap portion which is equipped with an eyelet l5 for the reception of the switch stick so that the device may be rocked into or rocked out of operative position.

This upper portion I4 is provided with projecting ears IS on which a biased lever I1 is pivotally tion shown in Figure rocked into operative position, the lever, has

& occurs.

its outer enddepressed by the cam latching .Qlip

8 of the upper stationary terminal 4 and such outer end of the lever rides under this latching thus retaining the fuse tube in position. There is a slight rocking and sliding motion between the other end of the lever 2| and the upper end of the fuse tube during this'operation.

Assume that the device is in'its operative'position as shown in Figure 1 and that an overload Whether this overload is a small overs load or a heavy overload, the device functions to mounted by means of the plntle pin IS. The

lever I! is spring urged upwardly by means of the spring l9, one end of the spring bearing against the portion I4 and the other end bearing against a transverse web integral with the lever II, as shown most clearly in Figures 1 and 3. The upper terminal assembly 2 of the fuse tube is provided with a main lever 2| which is pivoted adjacent one end by means of the pintle pin 2| on the spring pressed lever 11.-

- upp'er member H of the fuse tube is provided with an internally threaded sleeve like hos 22 which receives the clamping nut 24. This clamping nut engages the buttonhead 25 of the fuse link If desired, the fuse link may have an upper leader portion 25 with the upper and lower leadersjoined by means of the fusible section 21 and the strain wire 28, though, if desired and as will appear hereinafter, the fusible section may or may not have the strain wire associated with it and also may be located approximately centrally or adjacent the upperor lower end of the fuse link, as will appear hereinafter.

Itistobenotedthatthefuselinkisthreaded through an aperture in the lever 2| and its buttonhead clamped in place by means of the clamping plug or nut 2|. It is threaded through the fuse tube and projects outwardly through the open end'thereof and is secured in place by. means of the lower thumb nut 2. The Iowa quickly interrupt the circuit within the fuse tube when the fusible section 21 and the strain wire 2| are ruptured upon overload and the spring least of the fuse link from the fuse tube and to thus insure the wide separation of the severed end of the fuse tube. This separation occurs very quickly dueto the fact that the lever 2| is spring'urged; upwardly through the medium of the lever l1 and makes a quick upward rocking motion even though the overload may be relatively small. In the 'event of a heavy overload,

in addition to the action of the spring, there is .the eilfect of gas pressure'acting on the end of the lever 2| to-assistin the quick upward rocking motion of such lever. The stops 3| come into play for a scondfunction in addition to that previously described in that they limitthe upward motion of the lever "and thus prevent suchlever from acquiring a great amount of 7 momentum even if the. level-2| is blown upendofthe fusetubeispermanently open-and the upper end though closed under normal conditions, opens up when the fuse link is ruptured so as to give a free discharge passage for the gases from both ends of the fuse tube. .130:-

.. nially, however, the lever 2| effectively closes theupperend of the fuse tube I. If desired, the

lever 2| may be provided with flanges 2|, as shown in Figure 2, extending around 'a greater or less extent of the enlarged or outer end of the lever to thereby at least partially surround the rain, snow or sleet.

It is to be noted from an inspection of Figures '1, 4 and 5, that the upper portion'll .1;

' such' lever is free tolniove under the influence of the spring ll, aswillhereinafter appear. For

example, when the'device'is the stops 2| allow'the levers l1 and "to move to the posiwardly violently; as relatively restricted; A part of the energy imparted to the lever 20 in its upward travel-is utilized u'sefullynot onlyto withdraw the up-' perportionofthefuselinkbutalsotoactinthe capacityof-acamtorockabouttheupperstationarycontactlandtothuscamorforce-the fusetube l towardsits outerdetachedpositims "so thatthefuse tubeis'positivebdriven todetached position through the normal sctionof the fuse tube away from thejupper con tsct,atthesametimeimhookingfrombeneath thelatchinglip Thefusetube'then dropsto thepositipnshowninl'lgurefi.

Itistobenoted our-comparing Figures land 5 that the pivot point 2| moves upwardly when thefuselinkisrupturedandthatthelever 2| swings about the pivot point 2|. Consequently. the fuse link is extracted more nearly inline with the fuse tube than if the pivot point 2| had been a pivot point fixed with reference to the *upper end of the? fuse tube, thereby effectively protecting such upper end from the entrance of fusetube. :Insteadthepivotpoint 2| movesupwardlywithreferencetothefmetubeonmpture ofthefuselinksnd'snextensive throwormov'ement is permitted thelever 2| without sharply drawingthefu'selinkataua 'lleacrossthe umerendofthefmetubeu V lt may be readily y booking the switchstlckbenpththeportionll ofthelower terminaiassanblylofthefusetubeandlifting thetrunniomlfromthhookscfthelowerstationarytermimill. Thereafterthedevicemsy bercadilyrcfmedandmayberepbcedbymeam 4. when the fuse tube is thestrokeoftheleverllis.

2 riding beneath materially lesse used interchangeably with anyiform Figure 6. Thereafter the switch stick isca to engage the eyelet I! of the upper portion of' I the fuse tube and the fuse tube is rocked back into operative position the outer end of the lever the latching lip 8 of the upper stationary contact l.

It is to be noted that even under violent explosion the fuse tube is substantially protected the buttonheaded fuse 'link maybe threaded through the lever-and throughthe tube 32. The buttonheadl'l of the'fuselink bears directly igainst the upper surface of end or the lever 44.-

The lower portion of the fuse tubeisprovided 1 with an arm 48 which is integral with a' sleeve gases from opposite ends of the fusetube are somewhat balanced against each other and this lessens the upward recoil of the fuse mile and also lessens the 'd wnward rebound and thereby the strain imposed on the different parts of the apparatus. It is to be noted also that during the initial portion of' the rupturing of the circuit, that the upper end of the lever substantially closesthe fuse tube l for an instant and insures an arr-expulsion action even' under small overload.

In addition to this, the upper lever 20 being separation of. the-severed end of the fuse link within the fusetube. In actual operations of this device it has been found that the circuit is interrupted'and the arc extinguished within the s fuse tube under both heavy and light overloads "prior to the time that contact is broken between the upper terminal assembly of the fuse tube and the upper stationary contact so that there is no arcing between these parts when the fuse to its inoperative positionary terminal until it has been rocked-to its inoperative position; However, as stated, even the amount 0f recoil and thejamoi'mt of rebound is. very materially reduced by this construction.

In the form of the invention shown in Figure 7, the fuse tube is-indicated at 32 and the upper v tubei'cannot be detached from such lower staand lower terminal assemblies of the fuse tube are indicatedgenerally'at 33 and 34. The upper and lower stationary terminals spectively at 35 and 36.

In this formof the invention thetube is are indicatedreprovided with an upper apertured part 31 and an integral eyelet 38. This construction is provided with an auxiliary spring pressed lever 39.

which is pivoted to lips formed on the member 31 and is urged upwardly by means of the spring 40. The totalupward motion of .the lever 39 '41 rigidly secured adjacent the lower; portion of the fuse tube 32 andwhich projects outwardly from the fuse tube as indicated. It is bifurcated) at its outer end and carries the pintle pin it whereby the fuse link'extractinglever'il is pivoted thereto. a v

The f link extracting lever BI is provided with trunnions 52 which are receivedinthe hook like. portions of the lower stationaryter- The lever 5] is provided with a thumb nut 54 threaded on-a projecting threaded stem carried by the lever ii for securing t e lower leader portion 55'0f the fuse link in place. The fuse link is provided'with an upper-leader portion 56 which extends downwardly from the 'buttonhead l1 and is joined to the lower leader portion 55 by means of the fusible section, and by means of the strain wire 58. stated, the fusiblesection either with or without the strain wire may be lo-' cated wherever desired along the length of the fuse link either in the middle or adjacent the up r or lower ends'of. the fuse tube.

The operation of this apparatus upon the occurrence of an overload is'as follows: The'up'; per main lever 44 when the fuse link isruptured. 7 acts as a fuse link extractor, being urged quickly;

upwardly by means of the spring biased aux iliary lever 39 and also by any gas pressure that may act on the lower portion of the endof thelever 44. This causes the lever 44 to rock about the pin 43 while the auxiliary lever it rocks about its pivot pin 59. The upwardrocking-of the lever 44 causes such lever to act'against the stationary upper, contact 3! to force the fuse tube outwardly towards its inoperative position. In addition to this action, thevlower lever 5| acts in the capacit of a double-jointed hinge to fur-. ther assist in the extraction of any remaining portion of thefuse The upper lever M is urged upwardly by .gas pressure in addition to its .upward urge due to spring action hereinbefore describiegt' 122- peen' e der'violent overloads it will be i v pressure within the fuse tube is relieved 'atb'oth ends of the'fuse tube and the blasts from oppowhen it is free to move upwardly is limited by means oi stops II which are adapted to be en-,

cage by pr jections indicated at "to the main lever 44.

- [The main lever is provided with a cam like portion l5 which interlocks behind the cam like latchingiip 48 of the upper stationary contact 35. This upperstationary contact 35 is shown as unh'ooded or open, but it is to .be understoodthat either an open or the hooded type can be .of them- 42' integral withthe lever r a. The outer end of the lever as is pivoted as '65 site ends of the fuse tube tend to'balance each other, thereby reducing both the recoil and the rebound,,the upward recoil being resisted by the overhanginghook like; portions 01' the lowersta 7 tionary' terminal which cannot become detached from the trunnions to! the fuse tube until the fuse tube has downwardly to inoperative position; r

In"the event of a small overload,':flie circuit is quickly interrupted within the fuse time]!!! to the spring action of the upper main lever '44 which, as stated, is'urged upwardly by the spring pressed auxiliary'lever'll; and thusevm i ruptedwithinthefuse tube.

under small overloads the is quickly inter:

F igure 8 showsafurtherformoftheinvjenflou in which meme tube ll end of the rose tubet'and is-aperturedso that and lower terminal assemblies indicated general- 1y at BI and 62. Each of these assemblies includes a spring biased main lever for extracting the fuse The upper main lever 63 biased upwardly by means of an auxiliary lever 64 biased -by meansof the spring 65 and pivoted as indi-,

. 61 to thus allow limited motion of the lever Bl when such lever is free to move as hereinafter described. The outer end of the lever 64 is pivoted as indicated at to the lever 63. The lever 63 is provided with a cam like latching portion II which interlocks with a downwardly projecting rib or latching lip 12 integral with the upper stationary contact".

The latching lip 72 is bevelled on its outer face ited motion of the lever 81 when Such lever is' free to move.

The lower lever 11 is provided with a switch stick receiving hooked member SI and the upper member 61 rigidly carried by the fuse tube is provided with a switch stick receiving eyelet 92.

to provide a cam surface to allow the cam portion H to ride beneath such lip when the fuse is rocked back to operative position, the spring 65 yielding slightly and the other end of the lever as rocking and sliding a slight amount at the upper end of the fuse tube. The stationary contact may be either an open type or a housed type, a housed type having been shown. The lever 63 extends over the open upper end of the fuse tube and is provided with a sleeve like internally threaded boss 14 within which the buttonhead Assume that the device of Figure 8 is in the position shown, namely, in operative position, and that an overload occurs. when the overload occurs, both the upper lever 63 and the lower lever TI act to extract the fuse link as'each of them is spring urged outwardly away from the open end of the fuse tube and thus serve to quickly draw any remaining portions of the fuse link outwardly. In addition to this, it is to be noted that the gas pressure-is vented from both ends of the fuse tube. The fuse tube has an expulsion action in addition to the fuse link extracting action hereinbefore described. The upperlever i3 initially extends over the upper open end of the fuse tube and thus assists in the expulsion on. However, the gas pressure quickly moves the upper lever upwardly and also, if desired, may assist in the downward motion of the lower lever, the

aryterminal.

I5 of the fuse link is positioned, the lever being apertured and the fuse link extending through the aperture and through the fuse tube 6|! outwardly from its bottom end. The buttonhead 15 is clamped in position bymeans of the clamping nut'or plug 16.,

The lower terminal portion of the fuse tube in-,

' eludes a main lever 11 which'is provided with trunnions 18 that fitwithin the overhanging.

hook-shaped arms of a lower stationary contact l9,

The lever 11 is also provided with a rounded rear portion 80 which prevents removal or detachment of the fuse tube-from the lower contact desired, thestrain wire may be omitted. The

fusible section may be located at any point along the fuse link. For example, it may be located at the lower point as shown or may be located approximately centralIy of the fuse tube, as in Fig- After the circuit has been interrupted within the fuse tube, the fuse tubedrops downwardly to its lowermost or inoperative position. It may be removed from the lower stationary contact 18 by lifting it upwardly and outwardly with a switch stick, the switch stick eng ing the member 9|. Afterthefusetubehasbeenremovedfromthe lower stationary contact, it may be refused and and may be again lifted up by ineansofthe switch stick andthe trunnions I. placed within the hooks of the lower stationary terminal ll. Thereafter the operator engages the eyelet I! with the switch stick and rocks the fuse tube back into its operative positiom'the latching cam like member H riding beneath the latching cam like lip 12., The lever M .rocks downwardly against the action of thespring I! a light amount V and the end f f the lever 83 immediately over the 'nalassemblyofthefusetube are 7 for instance, or may be located adjacent the upper end of the fuse tube, as in Figure 9 hereinafterdescribed. V

A metal sleeve 85 is rigi ly attached adjacent the lower end of the fuse tube and is provided with apair of cars Ii which are pivotally joined.

to the downwardly biased auxiliary lever 81 by,

means'of the pintle pin-ll. A- spring ll urges the lever n downwardly. The outer emi of the upper end 0 the fuse tube slides and rocks slight- 'ly with reference to the upper end of the fuse tube. In addition to this action, during the mm latching motion of the fuse tube thelowcr termican yield slightly to thus facilitate the latching operation.

It is to be distinctly understood thatan'y of the parts of one form of the invention maybe used with any of the other parts of any other form of the inventionwherever desirable .or applicable. For example, the buttonhead of the fuse link may beclamped in place in any of the forms or the buttonhead' may merely bearagainst the upper end of the upper lever in any oftheformsr Inadditlontothmanytypeof lever "is pivotal]! joined to the by means of the pintle pin a. The inner end of the lever llisprovided with a pair-of extensions 81 which enmestops I! after liin.

upper contact whether or .open can be This form tion of the fuse tube is'shown as a rigid structure. In Figure '7 the lower terminal of the fuse "tube may be thedouble 'link construction and the upper terminal of the fuse tube maybe the spring biased main lever supported byfthe auxiliary lever. Inthe form of theinvention shown in Figure 8 the, spring biased malnlever supj ported by the" summer-3 lever is shown for both of the upper and lower. terminals of the fuse tube. j v The invention also=contemplatesthe provision of a rigid upper terminal for the fusetube and the spring biased main lever "supported by an auxiliary lever for the lower terminal of the fuse tube. of theinvention is shown in Figures sa' q m a In this forn'rof the invention'the fuse tube is indicated by the reierence'o'haracter 93. -It is provided withaclosure'ca'p 94' which is screw threaded on thefupper threaded tubular extension 95 of the upper terminal member 06 of the fuse tube and clamps the buttonhead 91 of the fuse link thereto. The fus'e link may be provided with a fusible section 98 adjacent its upper end and with a flexible leader'99 extending downfrom the hooks of -:the lower stationary terr'ninal.

' The curved portion; I23, o f; th -main lever lw expulsion action. (The main lever I.I 5 .is spring biased downwardly by means-oithe auxiliary wardly therefrom through the'open' lower end of used in 'connectionwith the'fusible section 08, as. previously described.

The upper terminal 96 of'the eludes the switch stick receiving eyelet portion I00 and the cam like latching portion IN. This H cam like latching portion may be provided with an outwardly extending beveled portion I02. The latching or cam like portion IN is adapted to latch beneath the latching lip I03 of the upper stationary contact I04. contact I04 is provided with a downwardly slanting cam like surface I05 to assist in guiding'the portion I 0| into interlocking position, the lower terminal structure yielding to accommodate thisaction as will hereinafter appear. The, upper stationary contact may be provided with outwardly flaring side walls asindicated at I06 and shown most clearly in Figure 10 to assist in guiding the upper terminal of the fuse tube into posie ion. l

If desired, in each'form of the invention the upper contact may be provided with a downwardly extending portion which acts as a stop to limitthe inward rocking motion of the fuse tube assembly when it is being rocked back into operative position after refusing.

The lower terminal. of the fuse tube is indicated generally by the reference character I01 and may comprise the spring pressed auxiliary lever I08 pivoted on the pivot pin I09 to lips' IIO integral with thelower sleeve like metal member IzII rigidly secured adjacent the lower end of the fuse tube.

The lever we may be channel-shaped 1r desired and is urged downwardly by means of the spring II2. It is provided with a pair of arms II3 located on opposite sides of the lips H0 and constitute extensions adapted to be limited in their motion by means of the-stops II4 integral with the member III. 'Thebuter end of the am:-

iliary lever I08 is 'pivotally connected to the mainlever 5 by means of the pintle pin 6. If desired, the pintl pin I I 6 may-have a. loose fit with the" lever H5. The lever IIS'carries the thumb nut III screw threaded on a threaded stem 1 I8 carried by the lever H5 and acting as a clamp to clamp the lower end of the flexible leader 00 of the fuse link. Ifdesired, the lever fuse tube inthe fuse tube. If desired, a strain wire may be may also serve toireceiv the -svtitcl i;.stick .when the fuse tube assembly;isbeingliftedintoand out of engagement=- with; the l o wer stationary terminaL.

Assume that the devic FigureslQ andlO is in operative position andan overloadoccursr {I'he downwardly biased lever'IJ 5 quickly extracts any remaining portion {Oi'the fuse link and .thus assists in clearing the device in addition to} the lever I08 and thusquickly moves downwardly.

The downward motion of the spring Ibiased lever II 5 lowers theiuse tube and causesv the cam like latching. ;,member. ;.I 0 I of the upper terminal of the ifusehtube to become detached from the upper'stationary terminalvv I04 and the fuse tub then rocks downwardly to itsv inoperative position. However, the circuitis interrupted The upper, stationary within the fusetube priorto. the time the upper terminal of the fuse tube breaks contact with the upper stationary terminal. a v,

The device may be lifitedfrom the lower-stationary terminal by means of a switch stick through the mediumof the portion I23 thereof and may 'be refused. After refusing it is again lifted into position by means of the switch stick v and its trunnions I20fitted within the hook portions of the lower stationary, terminal. The switch stick is then placed in engagement with the eyelet portion I00 of the upper terminal of the fuse tube and the fuse tube is rocked into operative position. If desired, the switch stick may in any of the forms of the invention shown herein be used merely to push the fuse tube into its operative position after once having been used to place the lower trunnionsof the fuse tube in engagement with the lower stationary terminal.

In this last described form of the invention shown in Figures 9 and 10 the advantage of simultaneous relief of pressure at both ends of the fuse tube as in the other forms of the invention is not obtained, However, this form of the I invention shows the spring biased fuse link extractinglever and the auxiliary spring urged lever cooperating therewith and located at the lower portion of a fuse tube.

It is to be noted in connection with this last described form of theinvention that when the refused device 'is rocked back into operative position, thereis a yield in the lower terminal I01 of the fuse tube and thus the portion IOI of the *upper terminal of the fuse tube is-permitted to ride beneath the latching lip I03 of theupper stationary terminal.

In all forms of the invention it will be seen that the main lever constitutes a combined fuse link extracting and latching lever and that this 7 main lever is biased towards fuse link -extracting and unlatching motion by means of the biased or spring urged auxiliary lever by which it is pi qta y carried.

A few of the many forms that the invention may take have been illustrated and it will b seen that the combined fuse link extracting and latching lever may be positioned at either end of the fuse tube with the other end of the fuse 'tube provided with any suitable type of terminal means, and with the fuse tube either open at both ends or closed at one end, and also it will be seen that combined fuse link extracting and latching levers may be positioned at both ends of the fuse tube.

It will be seen further that the combined fuse link extracting and latching lever may be made relatively light and may have a very quick fuse link extracting motion prior to the motion of other and more massive parts of the apparatus and thus may have a very quick fuse link extracting action which may or may not be assisted by the gas pressure generated within the fuse tube itself, depending on the severity of the explosion resulting from. rupture of the fuse link.

In all forms of the invention it will be seen that a very quick fuse link extracting action takes place without requiring motion of all parts of the fuse'tube assembly and instead requiring-motion of a spring biased, relatively small portion of the structure. This quick clearing of the device is also assisted by the expulsion action in all forms of the invention. This quick break insures a quick clearing of the circuit within the fuse tube itself prior to the outward rocking motion of the drop-out fuse tube. The device is thus enabled to have a positive operation even for small overloads and is also enabled to handle larger overloads because of its ability to quickly clear the circuit within the fuse tube itself.

With particular reference to the forms of the invention illustrated by Figures 1 to 8, it is to be noted that novel forms of drop-out fuse deviceshave been shown which have the above recited advantages and also have the advantage of being able to handle very much larger overloads than heretofore as the device is so constructed that the relief of pressure occurs simultaneously at both ends of the fuse tube and thus the danger of bursting ismaterially reduced Also there is a material lessening of both the recoil and the rebound and thus there is very much less strain put on the different portions of the apparatus.

In addition tothese advantages, for the forms of the invention illustrated by Figures 1 to 8, there is the further advantage that the gas pressure acts on the fuse link extracting lever and assists further in quick fuse link extraction. Further, for these forms of the invention, the fuse link extracting lever assists in insuring the drop-out action of the fuse tube thus making these devices more positive in their drop-out action. However, in all forms of the invention it is to be noted-that the fuse tube is biased towards drop-out motion;

It is to be noted also that although the novel fuse devices hereinabove described have the advantageousfeatures discussed, nevertheless they are relatively simple in their construction.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than .limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

4 l. A drop-out fuse device comprising a support, a rigid upper terminal and a lower terminal, an expulsion fuse tube open at both ends and movably supported from said support and biased towards motion away from one of said terminals, a fuse link within said fuse tube normally electrically connecting said terminals, and a combined, fuse link extracting and latching member biased towards fuse link extracting and unlatching motion and towards engagement with said upper stationary terminal and normally restrained by said fuse link and normally holding said fuse tube against drop-out motion, said combined fuse link extracting and latching member extending directly over at least a part of the open end ofsaid fuse tube, whereby upon rapture of said fuse link gas pressure will assist in the fuse link extracting and unlatching motion of said combined fuse link extracting and latching member.

2. A drop-out fuse device comprising a support, upper and lower stationary terminals, an

expulsion fuse tube having an open lower end and supported from said support, a fuse link within said fuse tube normally electrically connecting said terminals, a fuse link extracting lever normally restrained by said fuse link, and a spring biased auxiliary lever acting upon said fuse link extracting lever and usin said fuse link extracting lever towards fuse link extracting motion, said fuse tube having a rigid upper terminal and said upper stationary terminal being rigid and normally interlocking with the rigid upper terminal of said fuse tube.

5 port, a fuse link within said fuse tube normally electrically connecting said terminals, a fuse link extracting lever having one end attached to said fuse link, and a spring biased auxiliary lever p'ivotally supporting said fuse link extracting lever and urging said fuse link extracting lever towards fuse link extracting motion.

5. A fuse device comprising a support, a pair of terminals, an expulsion fuse tube open at both ends and normally supported from said support,

m. fuse link within said fuse tube normally electrically connecting said terminals, a fuse link extracting lever normally restrained by said fuse link, and spring means carried by said fuse tube urging said fuse link extracting lever towards fuse link extracting motion, said fuse link extracting lever extending directly across the open end of said fuse tube, whereby upon rupture of said fuse linksaid fuse link extracting lever will be actuated by said spring means and any gas pressure that is generated within said fuse tube.

6. A fuse device comprising a support, a pair of terminals, an expulsion fuse tube open at both ends and supported from .said support, a fuse link within said fuse tube normally electrically connecting saidterminals, a fuse link extracting lever extending directly across'an open end of said fuse tube and normally restrained by said fuse link, and spring means carried by said fuse tube urging said fuse link extracting lever toend thereof from saidsupport, a fuse link within rupture of said fuse link said'fuse link extracting lever will execute fuse link extracting motion by the force exerted by said spring means and by any gas presssure. that may be generatedwithin said fuse tube.

,7. A drop-out fuse device comprising-a sup port, a pair of terminals, an expulsion fuse tube open at both ends and pivotally supported from said support and biased towards motion away from one of said terminals, a fuse link within said fuse tube normally-electrically connecting I said terminals, a fuse link extracting lever con'-. nected to said fuse link and normally restrained a by said fuse link, and a spring biased auxiliary lever pivoted with reference to said fuse tube and pivoted to said fuse link'extracting lever and urging said fuse link extracting lever towards fuse link extracting motion, said fuse tube being normally held in, operative position and being releasedwhen said fuse link extractinggo lever executes fuse link extracting motion.

8. A drop-out fuse device comprising alsupport, a pair of terminals; an expulsion fuse tube open at both ends and movably supported from said support and biased towards motion away from 5 one of said terminals; a fuse link within-said fuse a tube normally electrically connecting said terminals, a combined fuse link extracting and latch--:

tube normallyelectrically connectin said terminals. a combined fuse link extracting and latching lever normally restrained by said fuse link and inv terlocking with one of said terminals, and'a biased auxiliary lever. pivotally supporting said .combined fuse link extracting and latching lever. V

and urging said combined fuse-link extracting. and latching lever towards fuselink extracting andunlatching motion, saidcombined fuse link extracting and latching lever releasing itself from the terminal to which it is normally latched when released bysaidfuselink. i a e '10. A drop-out fuse devicecomprising a support-having a flrstand a second stationary terminal, an expulsion fuse tube open atboth ends Land havlng'a terminal adjacent each'end thereofga fuse link within said fuse tube normally \electrically connecting the terminals of said fuse tube, one of said fuse tube terminals being pivv 'otally supported from said second stationary terminal, the other of the terminals of said fuse tube including acombined fuse link extracting 4 and latching lever normally interlocking with said first stationary-terminal and normallyires strained by said fuse'link; and a biased auxiliary,

lever pivotally supporting said combined fuse link extracting andlatching lever; and urging said 1 combined fuse link extracting and latching lever towards fuse link extracting and unlatching mo tion. -1 '7 I .11. A drop-opt fusedevice' comprising a support having a pair of stationary terminals, an-ex-, pulsion fusetube open at both-ends and having at leastfone terminal adjacent one end thereof and being pivotally supported adjacent the other link and lagging spring urged towards fuse said fuse tube normally electrically connecting said stationary terminals, the terminal of said fuse tube including. a combined fuse link; ex-

tracting and latching' lever normally interlocking with one of said stationary terminal and nor-.

mally restrained by said fuselink, and far-spring pressed auxiliary lever piv'otally supporting and biasing said combined fuse link extracting and latching lever towards fuse link extracting and .unlatching motion, said combined fuse link extracting and latching lever. normally closing-one end of said fuse tube.

v 12. A drop-out'fuse device comprising a sup-' port having a pair of stationary terminals; an

expulsion. fuse tube open at both ends and having at least one terminal-adjacent one end thereof and being pivotally supported adjacent theother 4 end thereof from-saidsupport, a fuse link within saidfuse tube normally electrically connecting" said stationary terminals, the terminal of: saidfuse tubeincluding a combined fuse link extract- -ing and latching lever normally interlocking with one of said stationary terminals and normally combined fuse link extractingandlatching lever towards fuse link extracting and unlatching motion, said combined fuse linkextracting and latching lever; normally closing one end of said 4 fuse tube, and stop means for limiting the 'motion ofsaid springpressed auxiliary lever...

13. A drop-out fuse device comprising a support having a pair of stationary terminals, an expulsion fuse tube open-at both ends and having at least one terminal adjacent one end thereofand bein pivotally supported adjacent the other end thereof from said support a fuse within saidjfuse tube normally electrically connecting said stationary terminals; the terminal of said fuse tube including a combined fuse link extract.- a

ing and latching lever normally interlocking with one of said stationary terminals and normally restrainedby said fuse link, a spring pressdaux' iliarylever pivotallysupporting and biasing said combined fuse link extracting and latchinglever towards fuse link extracting and unlatching mo- 1 tion, said combined fuse link extracting and latching lever normally closin one end of said fuse tube, and stop means for limiting themoftion of said springpressed auxiliary lever, the

fuse link extracting and unlatching motion of said 'combine'd fuse link extracting and latching lever being assisted by gas pressure generatedupon' rupture-of said fuse link.

14; A drop out fuse ,device comprising a; supfuse link extracting m'jeansand being pivotally supp jted from said second stationaryterrninal;

the first terminal of said fuse tube including a combined fuse link extracting and. latching lever w normally interlocklngfwith said first stationary terminal and normally restrained lay-said fuse tracting and unlatching motion. 15.,A drop-out fuse device comprising a sup --por t having a. first; and --a second stationary terminal, an expulsion fuse tube open at both ends and having a-flrst and asecond terminal adiallhk excent the respective ends of the fuse tube, a fuse link within said fuse tube normally electrically connecting the first and second terminals of said fuse tube, the second terminal of said fuse tube including fuse link extracting means. and being pivotally supported from said second stationary terminal, the first terminalof said fuse tube ineluding a combined fuse link extracting and latching lever normally interlocking with said first stationary terminal andnormally restrained by said fuse link, and a biased auxiliary lever pivotally supporting said combined fuse link ex- .tracting and latching lever and urging said combinedfuse linkextracting and latching lever towards fuse link extracting and unlatching motion.

165A drop-out fuse device comprising a support, a pair of'terminals, an expulsion fuse tube movably supported from said support for motion away from one of said terminals, a fuse link withinsaid fuse tube normally electrir ially connecting said terminals, and a fuse link extracting lever, and spring'means urging said lever towards fuse link extracting motion, said fuse link extracting lever being normally restrained by a said fuse link and cooperating with one of saidterminals and urging said fuse tube away from said terminal when said fuse link extracting lever executes fuse link extracting motion.

17., A drop-out fuse device comprising a support, a pair of terminals, an expulsion fuse tube movably supported from said support for motion away from one of said terminals, a fuse link within said fuse tube normally electrically connecting said terminals, and a fuse link extract ing lever, and spring means urging said lever towards fuse link extracting motion, said fuse link- 2,865,118 A to throw said fuse tube towards drop-outpost tion upon rupture of said fuse link. I

20. A drop-out fuse device comprising a support, an upper and a lower contact carried by said support, a drop-out fuse tube pivoted on said lower contact, a,fuse link within said fuse tube normally electricallyconnecting said contacts, and a combined fuse link extracting and latching lever pivotally supported from said fuse tube and normally interlocking with said upper contact and spring urged upwardly from the -up-.

per end of said fuse tube, said lever being normally restrained by said fuse link and having a rocking cam actionwith respect to said upper contact to throw said fuse tube towards dropout position upon rupture of said fuse link.

- 21. A drop-out fuse device comprising a support, a pair of terminals, an open-ended expulsi'on fuse tube movably supported from said support and biased towards motion away from one of said. terminals, a fuse link within said fuse tube normally electrically connecting said terminals, acombined fuse link extracting and latching lever normally restrained by said fuse link and interlocking with one ofsaid terminals, and

a biased auxiliary lever pivotally supporting said extracting-lever being normally restrained by said fuse link and cooperating with one of said terminals and urging said fuse tube away from saidterminal when said fuse link extracting le ver executes .fuse link; extracting motion, said -of said fuse tube and spring urged towards fuselink extracting motion and normally restrained by said fuse link,.t e motion of, said fuse link extractinglever being assisted by gas pressure upon rupture of said fuse link, said fuse link extracting lever when executing fuse link-extract- -combined-fuse link extractin and latching lever and urging 'said combined fuse link extracting and latching lever towards fuse link extracting and unlatching motion, said combined fuse link,- extracting and latching lever releasing itself from the terminal to .which it is normally latched when released by said fuse link and having a rocking cam action with respect to such terminal to-throw said fuse tube towards drop-out position. v

22. A fuse device comprising a support, a pair -of terminals, an expulsion fuse tube open at both ends and supported from said support, a fuse link-within said fuse tube.normally electrically connecting said terminals, a fuse link extracting lever extending directly across an open end of said fuse tube and normally restrained by said fuse link, said fuse link extending through said fuse link extracting leverand having an'enlarged head bearing against the outer side of said fuse link extracting lever, and spring means carried by said fuse tube urging said fuse link extracting lever towards fuse link extracting motion, whereby upon rupture of said fuse link said fuse link extracting lever will execute fuse link extracting motion by the force exerted by said spring means and by any gas pressure that may be generated within said fuse tube.

23.A fuse device comprising a support, a pair of terminals, an expulsion fuse tube open at both ends and supported from said support,- a fuse ing motion cooperatingwith said first terminal to throw said fuse tube towards drop-out position and bodily moving with saidfusetubeout of contact with said first stationary contact. 1-

19. A drop-out fuse device comprising a support; an upper and a lower contact carried by said support, a drop-out fuse tube pivoted on said lower contact, a fuse link within saidfuse tube normally electrically connecting said contacts, and a fuse link extracting. lever pivotally supportedfrom said fuse tube and biased for motion upwardly from the upper end of said fuse tube and normally restrained by said fuse link, said fuse link extracting lever having a rocking cam action with respect to said upper contact link within said fuse tube normally electrically connecting said terminals, a fuse link extracting lever extending directly across an open end of said fuse tube and normally restrained by said fuse link, said fuse link havingan enlarged head, means carried by said fuse link extracting lever for clamping said enlarged head directly to said fuse link extracting lever, and spring means carried by said fuse tube urging said fuse link extracting lever towards fuse link extracting motion, whereby uponrupture of said fuse link said fuse link extracting lever will execute fuse link extracting motion by the force exerted by said spring means and by any gas pressure that may be generated within said fuse tube.

o. SCHULTZ. 

